Method for forming inner flanges in a bushing which is used to secure a hose therein

ABSTRACT

A method of forming inner flanges in a bushing comprises steps of (a) extruding a bushing into an extruding die, (b) cutting an initial upward flange in the bushing, (c) shaping the initial upward flange into a final inner flange, and (d) repeating steps (a) to (c) to form additional inner flanges.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for forming inner flanges in a bushing which is used to secure a hose therein, where the bushing is used to attach the bushing to exterior devices.

[0003] 2. Description of Related Art

[0004] A conventional method for forming inner flanges in a bushing includes (a) providing an extruding die, (b) extruding a tubular bushing into the extruding die, (c) forming a first inner flange in the bushing and repeating steps (b) and (c) to form a desired number of distinct inner flanges in the bushing.

[0005] With reference to FIG. 14, the extruding die (20) comprises a first passage (21), a taper passage (22), and a second passage (23). The second passage (23) has a smaller diameter than the first passage (21) and the taper passage (22) reduces the diameter from that of the first passage (21) to that of the second passage (23). The bushing (40) has an inner periphery (not numbered), an outer periphery (not numbered), a leading end (not numbered) and a following end (not numbered). The leading end of the bushing (40) is extruded first in the extruding die (20), and the following end of the bushing (40) is extruded last in the extruding die (20). The punch (60) comprises a punch head (61) with an extension (611) that has a smaller diameter than the punch head (61).

[0006] With reference to FIG. 15, a stepped base (30) has four flat surfaces (301, 302, 303, 304) and a discharge hole (312). The extruding die (20) is perpendicular to the stepped base (30). The four flat surfaces (301, 302, 303, 304) comprise an uppermost flat surface (301), a second flat surface (302), a third flat surface (303) and a lowermost flat surface (304). The extruding die (20) with the bushing (40) and a pressing block (70) is slideably mounted on the stepped base (30) at the level of the uppermost flat surface (301).

[0007] With further reference to FIG. 16, the leading end of the bushing (40) is pressed into the first passage (21) of the extruding die (20). The extension (611) of the punch head (61) extrudes the bushing (40) into the second passage (23). Therefore, the leading edge of the bushing (40) gradually decreases in diameter as the bushing (40) is extruded through the taper passage (22) and into the second passage (23) of the extruding die (20), and a first inner flange (401) is created.

[0008] With reference to FIG. 16 and 17, the punch head (61) with the extension (611) is removed from the bushing (40), and the extruding die (20) is placed on the second flat surface (302) of the stepped base (30). The pressing block (70) presses the following end of the bushing (40) and extrudes the bushing (40) into the extruding die (20) until the leading end of the bushing (40) abuts the second flat surface (302) of the stepped base (30). Removed the pressing block (70).

[0009] With reference to FIG. 18, the punch bead (61) punches the inner periphery of the bushing (40) at the taper passage (22) to form a second inner flange (402).

[0010] With reference to FIG. 19 and 20, the steps are repeated by driving the bushing (40) to the third flat surface (303) and the lowermost flat surface (304) of the stepped base (30), to form a third inner flange (403) and a fourth inner flange (404) in the bushing (40).

[0011] When the fourth inner flange is completed, the bushing (41) is driven through the extruding die (20) and the discharge hole (312) on the lowermost flat surface (304) and is ready for exterior application. With reference to FIG. 15, the extruding die (20) is positioned over the uppermost flat surface (301) to make multiple inner flanges in another bushing (40). A new bushing (40) with a pressing block (70) is driven into the extruding die (20) until the bushing (40) abuts the uppermost flat surface (301) of the stepped base (30).

[0012] With reference to FIGS. 20 and 21, the disadvantage of the conventional method is that a weak connection is formed between the outer bushing (43) and the bushing (41). When inner flanges (401, 402) are formed in the bushing (40) with the conventional method, the shape of each flange (401, 402) is caused by only one action of the punch head (61) and the friction between the extruding die (20) and the bushing (40). The shape of each flange in bushing (40) results in small mounting area between flanges, and the small mounting area between flanges causes the weak connection between the outer surface of the bushing (43) and the bushing (41). Furthermore, the shape of each flange results in the deformation of flanges under a short period of lifetime.

[0013] To overcome the shortcomings, the present invention provides a method to form more effective flanges in a bushing to mitigate or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

[0014] The primary objective of the present invention is to provide a method of forming improved inner flanges. The method comprises steps of (a) extruding a bushing into an extruding die, (b) forming initial upward flanges, (c) pressing the initial upward flange down to a final flange and (d) repeating steps (a) to (c) using a stepped base to create multiple interior flanges in a bushing.

[0015] To carry out the foregoing method, a flange punch and a flat head punch are used to form and shape each individual inner flange in a bushing .

[0016] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a functional block diagram of a method for forming inner flanges in a bushing in accordance with the present invention;

[0018]FIG. 2 is an exploded cross sectional perspective view of a pressing block, a bushing and an extruding die mounted on a stepped base used in the method in FIG. 1;

[0019]FIG. 3 is an operational cross sectional side plan view of a pressing block pressing the bushing though the extruding die to the uppermost flat surface of the stepped base in accordance with the present invention;

[0020]FIG. 4 is an operational cross sectional side plan view of a flange punch creating a first upward inner flange in the bushing in accordance with the present invention;

[0021]FIG. 5 is an operational cross sectional side plan view of a flat head punch flattening the first upward inner flange in the bushing in accordance with the present invention;

[0022]FIG. 6 is an operational cross sectional side plan view of the flat head punch pressing the bushing down to the second flat surface of the stepped base in accordance with the present invention;

[0023]FIG. 7 is an operational cross sectional side plan view of the pressing block pressing the bushing down to a third flat surface of the stepped base in accordance with the present invention,

[0024]FIG. 8 is an operational cross sectional side plan view of the flange punch creating a second upward inner flange in the bushing in accordance with the present invention;

[0025]FIG. 9 is an operational cross sectional side plan view of the flat head punch flattening the second upward inner flange in the bushing in accordance with the present invention;

[0026]FIG. 10 is an operational cross sectional side plan view of the flat head punch pressing the bushing down to a fourth flat surface on the stepped base in accordance with the present invention;

[0027]FIG. 11 is an operational cross sectional side plan view of a clamp positioning a new bushing to be inserted into the extruding die in accordance with the present invention;

[0028]FIG. 12 is an operational cross sectional side plan view of a completed bushing being driven through the discharge hole;

[0029]FIG. 13 is a side plan view in partial section of a bushing mounted in a bushing formed by the method in FIG. 1;

[0030]FIG. 14 is an exploded perspective view of a punch, a bushing and an extruding die used in a conventional method to form a bushing;

[0031]FIG. 15 is an operational cross sectional side plan view of a pressing block pressing a bushing down into the extruding die in accordance with the conventional method;

[0032]FIG. 16 is an operational cross sectional side plan view of a punch extension creating a first inner flange in the bushing on the uppermost flat surface of the stepped base in accordance with the conventional method;

[0033]FIG. 17 is an operational cross sectional side plan view of the pressing block pressing the bushing down into the extruding die to a second flat surface of the stepped base in accordance with the conventional method;

[0034]FIG. 18 is an operational cross sectional side plan view of the punch extension creating a second inner flange in the bushing in accordance with the conventional method;

[0035]FIG. 19 is an operational cross sectional side plan view of a new bushing being inserted into the extruding die by a clamp in accordance with the conventional method;

[0036]FIG. 20 is an operational cross sectional side plan view of the completed bushing exiting through the discharge hole; and

[0037]FIG. 21 is a perspective view of a bushing mounted in a bushing formed with the conventional method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038] With reference to FIG. 1, a method of forming inner flanges in a bushing in accordance with the present invention comprises (a) extruding a bushing into an extruding die, (b) cutting an initial upward inner flange in the bushing, (c) shaping the initial upward inner flange into a final inner flange, and repeating steps (a) to (c) to form additional inner flanges.

[0039] With reference to FIGS. 2, 3 and 5, a device to perform the method of forming inner flanges in a bushing comprises a bushing (50), an extruding die (20), a stepped base (30), a pressing block (70), a flange punch (80) and a flathead punch (90). The stepped base (30) is stationary and comprises a discharge hole (36) and five stepped flat surfaces (31, 32, 33, 34, 35): an uppermost flat surface (3 1), a second flat surface (32), a third flat surface (33), a fourth flat surface (34) and a lowermost flat surface (35).

[0040] The extruding die (20) comprises an inner periphery (not numbered), and the inner periphery comprises a first passage (21), a taper passage (22) and a second passage (23). The second passage (23) has a smaller diameter than the first passage (21), and the taper passage (22) reduces the diameter from that of the first passage (21) to that of the second passage (23). The extruding die (20) is slideably mounted on the level of the uppermost flat surface of the stepped base (30) and moves across the stepped base (30) from the upper flat surface (31) to the lowermost surface (35).

[0041] The bushing (50) is a tube with an inner periphery (not numbered), an outer periphery (not numbered), a leading end (not numbered) and a following end (not numbered).

[0042] The pressing block (70) is a solid block. The flange punch (80) is a solid cylindrical rod with a cutting lip (81). The flat-head punch (90) is a solid cylindrical rod with a flat end (91). The pressing block (70) and the punches (70, 80, 90) press the bushing (50) down.

[0043] The specific actions performed in each of the steps in the method to forming inner flanges in a bushing follow.

[0044] Initially, reference is made to FIG. 3. In the step of (a) extruding a bushing (50) into an extruding die (20), the leading end of a bushing (50) is mounted slideably in the first passage (21) of an extruding die (20). A pressing block (70) presses and extrudes the bushing (50) into the extruding die (20). The leading end of the bushing (50) is compressed into the second passage (23) of the extruding die (20) until the leading end abuts the uppermost flat surface (21) of the stepped base (30). The pressing block (70) is removed.

[0045] With further reference to FIG. 4, the flange punch (80) is slideably inserted into the bushing (50) to perform the step of (b) forming an initial upward inner flange in the bushing. The flange punch member (80) freely slides in the bushing (50) until the cutting lip (81) at a transition between the taper passage (22) and the second passage (23). With the leading end of the (50) abutting the uppermost flat surface (31) of the stepped base (30), the cutting lip (81) of the flange punch (80) cuts an initial upward flange in the inner periphery of the bushing (50) when the flange punch (80) is pressed down. The flange punch (80) is removed.

[0046] With reference to FIG. 5 and 6, the flat-head punch (90) is slideably mounted in the bushing (50), and the extruding die is moved over the second flat surface (32) on the stepped base (30) to perform the step (c) shaping the initial upward inner flange into a final inner flange. The flat-head punch (90) presses the initial upward flange (51) down to the final inner flange shape and the bushing (50) down to the second flat surface (32) of the stepped base (30). The flat-head punch (90) is removed.

[0047] With reference to FIGS. 7 to 10, the extruding die (20) with the bushing (50) is moved over the third flat surface (33) on the stepped base (30), and the process is repeated on a stepped base (30) with an appropriate number of flat surfaces to form any desired number of final inner flanges.

[0048] With reference to FIGS. 11 and 12, another bushing (501) is aligned with the bushing (50) with the desired number of final inner flanges. The extruding die (20) with the bushing (50) with the desired number of final inner flanges and the aligned next bushing (501) are positioned over the discharge hole (36) in the stepped base (30). The pressing block (70) presses the aligned next bushing (501) and extrudes the remainder of the bushing (50) with the desired number of final inner flanges until the completed bushing (51) is pressed out of the extruding die (20) and falls through the discharge hole.

[0049] With further reference to FIG. 4, the extruding die (20) is moved over the uppermost flat surface (31) of the stepped base, and the process is repeated to form another bushing (51).

[0050] With reference to FIG. 13, the bushing (55) comprises a metallic layer (not numbered). The advantage of the method described is the creation of inner flanges (502, 503) that have greater gripping capability because of the shape of the inner flanges (502,503) helps the inner flanges (502,503) to dig into the bushing (55). The distance between the inner flanges (502, 503) provides more gripping area between the bushing (51) and the bushing (55). The metallic layer in the bushing (55) has deformed and has shaped like a wave, which provides much stronger bond between the inner flanges (502,503) and the bushing (55). Furthermore, the inner flange (502, 503) has longer lifetime for not being damaged from the friction created by the friction between the bushing (51) and the bushing (55).

[0051] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A method of forming inner flanges in a bushing comprising steps of; extruding a bushing into an extruding die, cutting an initial upward inner flange in the bushing, shaping the initial upward inner flange into a final inner flange, and repeating the first three steps to form additional inner flanges.
 2. The method of forming inner flanges in a bushing as claimed in claim 1; where the step of extruding a bushing into an extruding die comprises pressing a bushing that is a tube with an inner periphery, an outer periphery, a leading end and a following end into an extruding die with a first passage with a large diameter, a taper passage and a second passage with a diameter smaller than the diameter of the first passage where the extruding die is mounted on a stepped base with an uppermost flat surface, a second flat surface, a third flat surface, a fourth flat surface and a lowermost flat surface with a discharge hole by means of a pressing block until the leading end of the bushing abuts the uppermost flat surface of the stepped base and the diameter of the leading end is reduced; and then removing the pressing block from pressing down the bushing.
 3. The method of forming inner flanges in a bushing as claimed in claim 1; where the step of cutting an initial upward inner flange in the bushing comprises pressing a flange punch that has a cylindrical rod, and a cutting lip into a bushing that is a tube with an inner periphery, an outer periphery, a leading end and a following end such that the cutting lip cuts the inner periphery of the bushing and forms the initial upward inner flange where the bushing is in an extruding die mounted on a stepped base with an uppermost flat surface, a second flat surface, a third flat surface, a fourth flat surface and a lowermost flat surface with a discharge hole until the leading end of the bushing abuts the second flat surface of the stepped base; and then removing the flange punch from the bushing.
 4. The method of forming inner flanges in a bushing as claimed in claim 1; where the step of shaping the initial upward inner flange into a final inner flange comprises pressing a flat-head punch that is a cylindrical rod and a flat-head into a bushing that is a tube with an inner periphery, an outer periphery, a leading end and a following end in an extruding die with a first passage with a large diameter, a taper passage and a second passage with a diameter smaller than the diameter of the first passage where the extruding die is mounted on a stepped base with an uppermost flat surface, a second flat surface, a third flat surface, a fourth flat surface and a lowermost flat surface with a discharge hole to flatten an initial upward inner flange cut in the bushing to form the final inner flange until the leading end of the bushing abuts the third flat surface of the stepped base; and then removing the flat-head punch from the bushing.
 5. A method of forming inner flanges in a bushing comprises the steps of: extruding a bushing into an extruding die by pressing a bushing that is a tube with an inner periphery, an outer periphery, a leading end and a following end into an extruding die with a first passage with a large diameter, a taper passage and a second passage with a diameter smaller than the diameter of the first passage where the extruding die is mounted on a stepped base an uppermost flat surface, a second flat surface, a third flat surface, a fourth flat surface and a lowermost flat surface with a discharge hole by means of a pressing block until the leading end of the bushing abuts the uppermost flat surface of the stepped base and the diameter of the leading end is reduced; and then removing the pressing block from the bushing; cutting an initial upward inner flange in the bushing consists of pressing a flange punch that has a cylindrical rod, and a cutting lip into the bushing such that the cutting lip cuts the inner periphery of the bushing and forms the initial upward inner flange until the leading end of the bushing abuts the second flat surface of the stepped base; and then removing the flange punch from the bushing; shaping the initial upward inner flange into a final inner flange by pressing the initial upward inner flange in the bushing into an extruding die by a flat-head punch that is a cylindrical rod and a flat-head, which flattens the initial upward inner flange in the bushing and forms the final inner flange, until the leading end of the bushing abuts the third flat surface of the stepped base; and then removing the flat-head punch from the bushing; repeating the previous steps to form additional inner flanges; positioning a new bushing over the bushing with the completed inner flanges and pressing the bushing with the completed inner flanges through the extruding die by a pressing block pressing against the new bushing until the bushing falls through the discharge hole in the stepped base so the method is repeated to form another bushing. 